Piece of furniture provided with an attachable and detachable supporting structure



Jan. 19, 1965 N. P. LUDVIGSEN 3,166,030

PIECE OF FURNITURE PROVIDED WITH AN ATTACHABLE AND DETACHABLE SUPPORTING STRUCTURE Filed Jan. 31, 1963 mvmron ATTORNEY United States PatentQ PIECE OF FURNITURE PROVIDED WITH AN AT- TACHABLE AND DETACHABLE SUPPORTING STRUCTURE Niels Peter Ludvigsen, Agerbaek, Denmark, assiguor to Brdr. Ludvigsen A/ S, Agerbaek, Denmark Filed Jan. 31, 1963, Ser. No. 255,261 Claims priority, application Denmark, Jan. 31, 1962, 448 11 Claims. (Cl. 108-455) This invention relates to furniture provided with attachable and detachable supporting structures. Especially the invention may be used in connection with chairs, preferably chairs provided with wooden seats, but it may also be used in connection with many other types of furniture, for example stools, tables, preferably smaller tables, cupboards, flower-stands and the like.

More particularly this invention relates to furniture pieces which include a substantially flat member, for example a chair seat, having an underside on which a block is secured, and a supporting structure comprising a cross member and at least one leg, which cross member is detachably attached to said block.

Such detachable supporting structures make it possible during storing or transport of the furniture to pack each main portion of the furniture, for example the chair seats with appertaining armrests and backs, if any, separately and the supporting structures separately, so that a given quantity of furniture requires considerably less space than if the furniture were to be stored or transported assembled.

In hitherto known furniture of the kind referred to, the blocks have comparatively large dimensions, and the cross members of the supporting structures are secured to the lower side of the block by means of a number of detachable screws. The block serves to secure a solid fastening of the supporting structure to the piece of furniture, the lower substantially flat member of which is often too thin in itself to be able to hold the supporting structure when the latter is fastened by means of screws.

In such known furniture, therefore, the upper side of the supporting structure will be positioned quite a distance below the underside of the main portion of the piece of furniture, specifically, a distance corresponding to the thickness of the block.

Moreover the supporting structure has to be provided with holes for the screws which holes reduce the strength of the members of the supporting structure provided with the holes which are often arranged onplaces where strength is necessary.

An object of the invention is to provide a piece of furniture of the type stated above, in which the cross member of the supporting structure may be arranged immediately below the underside of the disk-like member of the piece of furniture, preferably directly engaging the latter.

Another object of the invention is to provide a piece of furniture of the type stated above in which a block may be used having comparatively small dimensions.

A further object of the invention is to provide a piece of furniture of the type stated above comprising clamping means adapted to urge the supporting structure towards the block, which clamping means only have to comprise a single screw or bolt so that, consequently, the supporting structure only has to be provided with a corresponding single hole and so that the latter may be positioned at a relatively unloaded part of the supporting structure.

Still a further object of the invention is to provide a piece of furniture of the above stated type, in which it is possible only by use of a single screw or bolt to obtain a great strength of the connection between the supporting structure and the block.

These and further objects and advantages of the in- "ice 'line 22 in FIG. 1, and

FIG. 3 is a sectional View on a larger scale taken on line 33 in FIG. 1.

The drawing shows the invention used in connection with a chair, but it is to be understood that the invention may be used in connection with many other types of furniture.

In the drawing, 10 is a chair seat of a wooden chair on the underside of which there is attached a supporting structure provided with a cross member 12 carrying legs, which are, however, cut off for the sake of clearness, so that only their upper ends 38 are indicated.

The cross member 12, which is made from iron or aluminium tubes, comprises two oppositely directed V-or U- shaped sets of rods, 14, 16 and 18, 20, respectively, which two sets of rods are interconnected by means of a curved connecting rod 22. The rod 14, the connecting rod 22 andthe rod 18 are made by bending of a single tube whereto the two further rods 15 and 20 are welded. In the space between the rods 16 and 20 and the connecting rod 22 a block 24 is arranged, which block 24 is secured, preferably by means of glue, to the underside of the seat 10. The block 24 extends into a recess 25 provided in the lower side of the seat 10 and having the same contour as the block 24 and a plain bottom, see FIGS. 2 and 3. Each of the two sides of the block 24 facing the rods 16 and 20, which forms an angle with each other, is provided with a groove 26, see FIG. 3, leaving an outwardly projecting flange 28 at the lower side of the block 24. The two rods 16 and 20 engage the two grooves 28 so that they are clamped between the flanges 28 and the underside of the seat 10 as appears from FIG. 3. In a corresponding manner the side of the block 24 facing the connecting rod 22 is provided with a groove 30 leaving an outwardly projecting flange 32 at the lower side of the block 19. The connecting rod 22 engages this groove 30 and is thereby clamped between the flange 32 and the underside of the seat 10 as appears from FIG. 2.

Thnsthe cross member 12 is secured to the seat 10 only by the engagement with the grooves 26 and 30 of the block 24.

To provide and ensure this engagement clamping means are provided comprising a screw 34 which is passed through a hole in the connecting rod 22 and secured into the block 24, see FIG. 2,'thereby not only directly ensuring the engagement of the connecting rod 22 with the groove 30, but due to the fact that the two rods 16 and 20 form an angle with each other, also securing the engagement between these two rods 16 and 20 andthe grooves 26. The screw 34, preferably a machine screw, is screwed into a threaded member 35 secured within the block 24, see FIG. 2. p

The rods 14, 16, 18 and 20 continue into legs 38 of the chair, which, however, as stated above for the sakeof clearness in the drawing have been cut off at their upper ends. r

As indicated in FIGS. 2 and 3, the lower side of the seat 10 is curved. Owing there-to a supporting member 40 is arranged on each rod 14, 16, 18 and 20 at a distance from the block 24. This supporting member 46, which preferably consist of rings of rubber or another yielding material, are passed over the rods and contact the lower side of the seat 10 and maintain the cross member 12 under a slight tension between the underside of the seat and the flanges 28 and 32 of the block 24 whereby rock- 7 ing of the seat owing to an off-set load thereon is avoided. The block 24 may be made from different materials, for example from plastic or solid Wood. A plastic block is, however, comparatively expensive, and .a block of solid Wood will have a tendency to warp. A cheap and nevertheless effective block may be made from plywood. In this case, however, the flanges 28 and 30 will be formed only by one or two of the plies of the plywood so that the block will have a tendency to split. This tendency may be effectively prevented if as shown in FIGS. 1 and 3 a number of screws 42ifrom the upperside of the block 24 arescrewed almost right through the block to the lower side thereof. These screws 24 will be invisible, but will effectivelyprevent the block from being split by influences on the flanges28 and 30. 1

, Whereas the description and accompanying drawing 7 have described and shown a typical embodiment of the supporting members being made from a resilient material. V

7. A piece of furniture provided with an attachable and block having an outer contour at its upper side, said under side of said substantially flat member being provided with a recess having an outline conforming to said contour, and having a bottom, said block engaging said recess and being secured to said bottom thereof.

present invention, it'should be apparent to those skilled in the art that various changes may be made in the form of the invention without affecting the scope thereof.

.1 claim: w i

l. A piece of furniture provided With'an attachable and detachable supporting structure, said piece 'of furniture comprising a substantially flat member having an underside, a block secured to said underside, said block having a first side face and a second side face opposite each other, said two side faces having longitudinal directions forming'a block angle with each other thereby having a smallest distance at one end of said block, each said side face being provided with a groove leaving a flange projecting outwardly from said block at the lower side thereof, said supporting structure comprising a cross-member adapted to support said substantially flat member, and at least one leg secured to said cross-member, said cross-member comprising a first and a second rod havingaires forming a rod angle with each other, said rod angle being equal to said block angle, said two rods being adapted to engage one of said two grooves each above said two fia ngesg and clamping members adapted to urge said cross-membertowards said end of said block for retaining said two rods in engagement with said two grooves. 1

. 2. A piece of furniture provided with an attachable and detachable supporting structure as defined in claim 1, said cross-member comprising a connecting rod, said first and said second rod being secured to said connecting rod projecting to the same side thereof and sloping away from eachother, said clamping means being adapted to urge said connecting rod towards said end of said block.

3. A piece of furniture provided with an attachable and detachable supporting structure as defined in claim 2, said block having a third side face at said end thereof, said.

third side face being provided with a third groove leaving a third flange projecting outwards from said block at the lower side thereof, said connecting rod being adapted to engage said third groove above said third flange;

4. A piece of furniture provided with an attachable and detachable supporting structure as defined in claim 3, said connecting rod being curved, said third side face being equally curved.

5. A'piece of furniture provided'with an attachable and detachable supporting structure as defined in claim 1, said cross-member comprising at least three portions extending outside said block when said supporting structure is attached to said substantially flat member, a supporting member being arranged on each said portion engaging said underside of said substantially flat member.

6. A piece of furniture provided with anattachable and 9. A piece of furniture provided with an attachable and detachable supporting structure as defined in claim 1, said block being made from a laminated material comprising a number of plies, said flanges comprisingat least one ply of said plies at the lower side of said block, a number of screws being. screwed into said block from the upper side thereof and extending through last said ply.

' '10. A piece of furniture provided with an attachable and detachable supporting structure, said piece of furniture comprising a substantially flat member, said supporting structure being adapted to support said member, said substantially flat member having an underside, a block secured to said underside, said block having an end and a first and a second side face, said two side faces diverging from said end, said first side face being provided with a first groove leavinga first flange projecting outwards from said block at. the lower side thereof, said second side face being provided with a second groove leaving a second flange projecting outwards from said block at the lower side thereof, said supporting structure comprising a cross-member, said cross-member having a center portion and a first and a second rod diverging from said center portion, said first rod conforming to said first side. face, said second'rod conforming to said second side face,

said first rod being adapted to engage said first groove above said first flange, said second 'rod being adapted to engagesaid second groove above said second flange, and

clamping means interconnectingsaid cross-member and said block and being adapted to urge said center portion towards said block for retaining said first and said sec .ond rod in engagement with said first groove and said second groove respectively.

.11. A piece of furniture as defined in claim 10, provided with an attachable and detachable supporting structure, said first rod contacting, when engaging said first groove, said first flange and said underside, said second rod contacting, when engaging said second groove, said second flange and said underside.

' References Cited by the Examiner UNITED "STATES PATENTS 317,270 5/85 Zeigler 248 188 2,967,747 1/61 Bus 1 312-257- 3,048,441 8/62 Rose -1 297-416 FOREIGN PATENTS 96,478 3/24 Austria. 268,492 8/50 Switzerland. 528,654 8/56 Canada. 550,588 11/56 Italy. 7 a 676,529 7/52 Great Britain. 1,265,936 5/61 France.

detachable supporting structure as defined in claim 5, said FRANK B. SHERRY, Primary Examiner. 

1. A PIECE OF FURNITURE PROVIDED WITH AN ATTACHABLE AND DETACHABLE SUPPORTING STRUCTURE, SAID PIECE OF FURNITURE COMPRISING A SUBSTANTIALLY FLAT MEMBER HAVING AN UNDERSIDE, A BLOCK SECURED TO SAID UNDERSIDE, SAID BLOCK HAVING A FIRST SIDE FACE AND A SECOND SIDE FACE OPPOSITE EACH OTHER, SAID TWO SIDE FACES HAVING LONGITUDINAL DIRECTIONS FORMING A BLOCK ANGLE WITH EACH OTHER THEREBY HAVING A SMALLEST DISTANCE AT ONE END OF SAID BLOCK, EACH SAID SIDE FACE BEING PROVIDED WITH A GROOVE LEAVING A FLANGE PROJECTING OUTWARDLY FROM SAID BLOCK AT THE LOWER SIDE THEREOF, SAID SUPPORTING STRUCTURE COMPRISING A CROSS-MEMBER ADAPTED TO SUPPORT SAID SUBSTANTIALLY FLAT MEMBER, AND AT LEAST ONE LEG SECURED TO SAID CROSS-MEMBER, SAID CROSS-MEMBER COMPRISING A FIRST AND A SECOND ROD HAVING AXES FORMING A ROD ANGLE WITH EACH OTHER, SAID ROD ANGLE BEING EQUAL TO SAID BLOCK ANGLE, SAID TWO RODS BEING ADAPTED TO ENGAGE ONE OF SAID TWO GROOVES EACH ABOVE SAID TWO FLANGES, AND CLAMPING MEMBERS ADAPTED TO URGE SAID CROSS-MEMBER TOWARDS SAID END OF SAID BLOCK FOR RETAINING SAID TWO RODS IN ENGAGEMENT WITH SAID TWO GROOVES. 